Archive for the ‘Cycles’ Category


This quote from the report stood out: ‘there are long-lasting periods of strong and weak solar activity, which is also reflected in the climate on Earth.’ Worth noting as we proceed through a period of weak activity right now.
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An international team of researchers led by ETH Zurich has reconstructed solar activity back to the year 969 using measurements of radioactive carbon in tree rings, reports Phys.org.

Those results help scientists to better understand the dynamics of the sun and allow more precise dating of organic materials using the C14 method.

What goes on in the sun can only be observed indirectly. Sunspots, for instance, reveal the degree of solar activity—the more sunspots are visible on the surface of the sun, the more active is our central star deep inside.

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Data courtesy of Solen.info

Back in November it looked like solar cycle 25 was finally getting underway, with daily sunspot numbers peaking up to 80, and the 30 day Wolf number climbing over 30 in early December. Since then though, the Sun has relapsed into a low activity state.

This won’t come as any surprise to Talkshop followers, we’ve been saying that cycle 25 would be very low for most of the last decade. Our group research culminated in late 2013 with publication of Rick Salvador’s orbital resonance model in the journal ‘Pattern Recognition in Physics’. We provided an update on the validation of the model a while back, showing it has remained on track since publication.

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Model dinosaur


The lead author of the study puts the blame on “the largest cataclysmic impacts and massive volcanism, perhaps sometimes working in concert.” The study says: ‘The correlations and similar cycles in marine and non-marine extinction episodes suggest a common cause’. Note: this is a follow-up to a 2015 study with the same lead author, also featured at the Talkshop.
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Mass extinctions of land-dwelling animals—including amphibians, reptiles, mammals, and birds—follow a cycle of about 27 million years, coinciding with previously reported mass extinctions of ocean life, according to a new analysis published in the journal Historical Biology.

The study also finds that these mass extinctions align with major asteroid impacts and devastating volcanic outpourings of lava called flood-basalt eruptions—providing potential causes for why the extinctions occurred, reports Phys.org.

“It seems that large-body impacts and the pulses of internal Earth activity that create flood-basalt volcanism may be marching to the same 27-million-year drumbeat as the extinctions, perhaps paced by our orbit in the Galaxy,” said Michael Rampino, a professor in New York University’s Department of Biology and the study’s lead author.

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Credit: cherishthescientist.net

‘Scientists use an extended, 22-year solar cycle to make the forecast’ is the sub-heading to the article. In other words the Hale cycle. At the end of last year The Talkshop detailed Plenty of predictions from a wide range of research groups, including our own, made in 2013. A possible (?) early indicator is that the ‘smoothed minimum’ of sunspots at the start of solar cycle 25 is given by Wikipedia as 1.8, the lowest recorded since cycle 7 (0.2) in 1823.
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In direct contradiction to the official forecast, a team of scientists led by the National Center for Atmospheric Research (NCAR) is predicting that the Sunspot Cycle that started this fall could be one of the strongest since record-keeping began, says NCAR News.

In a new article published in Solar Physics, the research team predicts that Sunspot Cycle 25 will peak with a maximum sunspot number somewhere between approximately 210 and 260, which would put the new cycle in the company of the top few ever observed.

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Sunspots [image credit: NASA]


Wikipedia’s Solar activity and climate web page says:
Solar activity has been on a declining trend since the 1960s, as indicated by solar cycles 19-24, in which the maximum number of sunspots were 201, 111, 165, 159, 121 and 82, respectively.

We’re probably not surprised that they prefer a metric which appears to support their often-expressed view in various climate-related pages that modern global warming can’t be natural.

But is the sunspot maximum the most relevant metric to judge the level of solar activity by? Another Wikipedia page is its List of Solar Cycles.

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Quiet sun [image credit: NASA]


They picked an interesting time to study the Sun, as it starts to emerge from an unusually deep and long-lasting solar minimum. What effect this might have on Earth’s weather systems of course remains to be seen, but could be hard to quantify. The researchers have a lot of data to work through, and are hoping for ‘unprecedented insights into the sun’.
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Three of the Solar Orbiter spacecraft’s instruments, including Imperial’s magnetometer, have released their first data, reports Phys.org.

The European Space Agency’s Solar Orbiter spacecraft launched in February 2020 on its mission to study the sun and it began collecting science data in June.

Now, three of its ten instruments have released their first tranche of data, revealing the state of the sun in a ‘quiet’ phase.

The sun is known to follow an 11-year cycle of sunspot activity and is currently almost completely free of sunspots.

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Solar Cycle 25 is here, says NASA

Posted: September 17, 2020 by oldbrew in Cycles, News, solar system dynamics
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The Sun from NASA’s SDO spacecraft


Solar Cycle 25 has begun, according to this NASA press release.

During a media event on Tuesday, experts from NASA and the National Oceanic and Atmospheric Administration (NOAA) discussed their analysis and predictions about the new solar cycle – and how the coming upswing in space weather will impact our lives and technology on Earth, as well as astronauts in space.

The Solar Cycle 25 Prediction Panel, an international group of experts co-sponsored by NASA and NOAA, announced that solar minimum occurred in December 2019, marking the start of a new solar cycle.

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Which brings us back to the old conundrum: do cosmic rays affect the Earth’s weather / climate, and if so, how and how much?

Spaceweather.com

August 11, 2020: Cosmic rays are bad–and they’re probably going to get worse.

That’s the conclusion of a new study entitled “Galactic Cosmic Radiation in Interplanetary Space Through a Modern Secular Minimum” just published in the journal Space Weather.

“During the next solar cycle, we could see cosmic ray dose rates increase by as much as 75%,” says lead author Fatemeh Rahmanifard of the University of New Hampshire’s Space Science Center. “This will limit the amount of time astronauts can work safely in interplanetary space.”

spacewalk

Cosmic rays are the bane of astronauts. They come from deep space, energetic particles hurled in all directions by supernova explosions and other violent events. No amount of spacecraft shielding can stop the most energetic particles, leaving astronauts exposed whenever they leave the Earth-Moon system.

Back in the 1990s, astronauts could travel through space for as much as 1000 days before they…

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The Solar Minimum Superstorm of 1903

Posted: July 31, 2020 by oldbrew in Cycles, solar system dynamics
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A message from the past: “The timing of the storm interestingly parallels where we are now–near Solar Minimum just after a weak solar cycle.”

Spaceweather.com

July 29, 2020: Don’t let Solar Minimum fool you. The sun can throw a major tantrum even during the quiet phase of the 11-year solar cycle. That’s the conclusion of a new study published in the July 1st edition of the Astrophysical Journal Letters.

“In late October 1903, one of the strongest solar storms in modern history hit Earth,” say the lead authors of the study,  Hisashi Hayakawa (Osaka University, Japan) and Paulo Ribeiro (Coimbra University, Portugal). “The timing of the storm interestingly parallels where we are now–near Solar Minimum just after a weak solar cycle.”

redlineAbove: The red line marks the 1903 solar superstorm in a plot of the 11-year solar cycle. [ref] The 1903 event wasn’t always recognized as a great storm. Hayakawa and colleagues took an interest in it because of what happened when the storm hit. In magnetic observatories around the world, pens…

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We’ll look here at examples of where a 2400 year period has been identified by researchers in radiocarbon data.
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Part of the abstract below is highlighted for analysis. The original Talkshop post on the paper in question:
S. S. Vasiliev and V. A. Dergachev: 2400-year cycle in atmospheric radiocarbon concentration

Abstract. We have carried out power spectrum, time-spectrum and bispectrum analyses of the long-term series of the radiocarbon concentrations deduced from measurements of the radiocarbon content in tree rings for the last 8000 years. Classical harmonic analysis of this time series shows a number of periods: 2400, 940, 710, 570, 500, 420, 360, 230, 210 and 190 years. A principle feature of the time series is the long period of ~ 2400 years, which is well known. The lines with periods of 710, 420 and 210 years are found to be the primary secular components of power spectrum. The complicated structure of the observed power spectrum is the result of ~ 2400-year modulation of primary secular components. The modulation induces the appearance of two side lines for every primary one, namely lines with periods of 940 and 570 years, of 500 and 360 years, and 230 and 190 years. The bi-spectral analysis shows that the parameters of carbon exchange system varied with the ~ 2400-year period during the last 8000 years. Variations of these parameters appear to be a climate effect on the rate of transfer of 14C between the atmosphere and the the ocean.

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Solar Cycle Update

Posted: July 15, 2020 by oldbrew in Cycles, Solar physics
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SC 25 – are we nearly there yet?

Spaceweather.com

July 14, 2020: NOAA has released a new interactive tool to explore the solar cycle. It lets you scroll back through time, comparing sunspot counts now to peaks and valleys of the past. One thing is clear. Solar Minimum is here, and it’s one of the deepest in a century.

progression

Solar Minimum is a natural part of the solar cycle. Every ~11 years, the sun transitions from high to low activity and back again. Solar Maximum. Solar Minimum. Repeat. The cycle was discovered in 1843 by Samuel Heinrich Schwabe, who noticed the pattern after counting sunspots for 17 years. We are now exiting Solar Cycle 24 and entering Solar Cycle 25.

During Solar Minimum, the sun is usually blank–that is, without sunspots. The solar disk often looks like a big orange billiard ball:

hmi1898 The spotless sun on July 13, 2020

In 2019, the sun went 281 days without sunspots, and…

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Image credit: Tallbloke

A few days ago I tweeted this comment above some remarkable video of the Three Gorges Dam bypass sluices.

Among other people, this was picked up by Willis, the warmist at WUWT, who used it as an opportunity to attack the reality of the Sun-climate connection:

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Ionized gas inside the Sun moves toward the poles near the surface and toward the equator at the base of the convection zone (at a depth of 200,000 km/125,000 miles).
Credit: MPS (Z.-C. Liang)


The title of the study cited in this report gives us the clue: ‘Meridional flow in the Sun’s convection zone is a single cell in each hemisphere’. The full cycle takes about 22 years on average, with a magnetic reversal halfway through.
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The sun’s magnetic activity follows an 11-year cycle. Over the course of a solar cycle, the sun’s magnetic activity comes and goes, says Phys.org.

During solar maximum, large sunspots and active regions appear on the sun’s surface. Spectacular loops of hot plasma stretch throughout the sun’s atmosphere and eruptions of particles and radiation shoot into interplanetary space.

During solar minimum, the sun calms down considerably. A striking regularity appears in the so-called butterfly diagram, which describes the position of sunspots in a time-latitude plot.

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Sunspots [image credit: NASA]


The researchers’ sun clock looks like this.
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Extreme space weather events can significantly impact systems such as satellites, communications systems, power distribution and aviation, says a Warwick University press release.

They are driven by solar activity which is known to have an irregular but roughly 11 year cycle.

By devising a new, regular ‘sun clock’, researchers have found that the switch on and off of periods of high solar activity is quite sharp, and are able to determine the switch on/off times.

Their analysis shows that whilst extreme events can happen at any time, they are much less likely to occur in the quiet interval.

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The Sun’s 11 year cycle is the most well known among many others we’ll cover in this series.

Now we’ve entered the minimum between solar cycles 24 and 25, this seems like a good moment to recap what we’ve discovered about the Sun and the planetary system that revolves around it here on the Talkshop during the last decade. The idea that the Sun’s activity cycles were somehow linked to the motion of the planets didn’t begin here of course. In fact, the idea goes all the way back to Rudolf Wolf, the Swiss astronomer who in the 1800s collated the old, and continued adding new sunspot observations. He was convinced that the orbit of Jupiter modulated sunspot numbers.

Wolf was an admirer of the work of Heinrich Schwabe, who was the first to discover an approximately decadal cyclic variation in sunspot numbers. Wolf refined and extended the observations and found that while some solar cycles were a little over ten years long, others were much closer to Jupiter’s orbital period of just under twelve years. The long term average was found to be around 11.1 years.

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Two Solar Cycles Active at Once

Posted: April 28, 2020 by oldbrew in Cycles, solar system dynamics
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Cycle 25 preparing to topple Cycle 24.

Spaceweather.com

April 27, 2020: Today, there are two sunspots in the sun’s southern hemisphere. Their magnetic polarity reveals something interesting: They come from different solar cycles. Take a look at this magnetic map of the sun’s surface (with sunspots inset) from NASA’s Solar Dynamics Observatory:

latest_4096_HMIBC_labelled_crop

One sunspot (AR2760) belongs to old Solar Cycle 24, while the other (AR2761) belongs to new Solar Cycle 25. We know this because of Hale’s polarity law. AR2760 is +/- while AR2761 is -/+, reversed signs that mark them as belonging to different cycles.

This is actually normal. Solar cycles always overlap at their boundaries, sprinkling Solar Minimum with a mixture of old- and new-cycle sunspots. Sometimes, like today, they pop up simultaneously. We might see more such combinations in the months ahead as we slowly grind our way through one of the deepest Solar Minima in a century.

The simultaneous appearance of two solar…

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The Saros cycle by numbers

Posted: April 14, 2020 by oldbrew in Analysis, Cycles, data, moon


The basis for discussion is the abstract of the paper below. Instead of their ‘high-integer near commensurabilities among lunar months’ we’ll just say ‘numbers’ and try to make everything as straightforward as possible. This will expand on a previous Talkshop post on much the same topic.

Hunting for Periodic Orbits Close to that of the Moon in the Restricted Circular Three-Body Problem (1995)
Authors: G. B. Valsecchi, E. PerozziA, E. Roy, A. Steves

Abstract
The role of high-integer near commensurabilities among lunar months — like the long known Saros cycle — in the dynamics of the Moon has been examined in previous papers (Perozzi et al., 1991; Roy et al., 1991; Steves et al., 1993). A by-product of this study has been the discovery that the lunar orbit is very close to a set of 8 long-period periodic orbits of the restricted circular 3-dimensional Sun-Earth-Moon problem in which also the secular motion of the argument of perigee ω is involved (Valsecchi et al., 1993a). In each of these periodic orbits 223 synodic months are equal to 239 anomalistic and 242 nodical ones, a relationship that approximately holds in the case of the observed Saros cycle, and the various orbits differ from each other for the initial phases. Note that these integer ratios imply that, in one cycle of the periodic orbit, the argument of perigee ω makes exactly 3 revolutions, i.e. the difference between the 242 nodical and the 239 anomalistic months (these two months differ from each other just for the prograde rotation of ω).
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To start with we can create a model that pretends the ‘high-integer near commensurabilities’ really are whole numbers, then break down the logic of the result to see what’s going in with the Moon at the period of one Saros cycle.

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H/T The GWPF

Dr David Whitehouse reviews the history of solar cycle predictions in a new paper by the Global Warming Policy Foundation which is published today. The paper, entitled The Next Solar Cycle, And Why It Matters For Climate, can be downloaded here.
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London, 6 April: A former BBC science correspondent says that there remains a real possibility that unusual solar behaviour could influence the Earth’s climate, bringing cooler temperatures for the next decade.

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Encylopaedia Britannica on the Metonic cycle:

Metonic cycle, in chronology, a period of 19 years in which there are 235 lunations, or synodic months, after which the Moon’s phases recur on the same days of the solar year, or year of the seasons. The cycle was discovered by Meton (fl. 432 bc), an Athenian astronomer.

Calendar Wiki’s opening paragraphs on the Metonic cycle say:

The Metonic cycle or Enneadecaeteris in astronomy and calendar studies is a particular approximate common multiple of the year (specifically, the seasonal i.e. tropical year) and the synodic month. Nineteen tropical years differ from 235 synodic months by about 2 hours. The Metonic cycle’s error is one full day every 219 years, or 12.4 parts per million.

19 tropical years = 6939.602 days
235 synodic months = 6939.688 days

It is helpful to recognize that this is an approximation of reality.

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Variation in solar activity during a recent sunspot cycle [credit: Wikipedia]


This seems worth another airing in the face of today’s insistent, but evidence-light, claims from climate obsessives that the world’s present and future weather is going to be largely determined by human activities.

If the energy from the sun varies by only 0.1 percent during the 11-year solar cycle, could such a small variation drive major changes in weather patterns on Earth? – asks Universe Today.

Yes, say researchers from the National Center for Atmospheric Research (NCAR) who used more than a century of weather observations and three powerful computer models in their study.

They found subtle connections between solar cycle, the stratosphere, and the tropical Pacific Ocean that work in sync to generate periodic weather patterns that affect much of the globe.

Scientists say this will help in predicting the intensity of certain climate phenomena, such as the Indian monsoon and tropical Pacific rainfall, years in advance.

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